Although the mechanism underlying increased risk of myocardial injury among diabetic patients is not yet clear, it is generally agreed that hyperglycemia contributed to increased risks of myocardial damage during ischemic injury. Mitochondria play a key role in energy production, oxidative stress, and apoptosis in cardiac muscle; alteration of mitochondria function can modulate myocardial function. This proposal will study the role of insulin receptor signaling to mitochondria and define the mechanisms through which insulin receptor signaling modulates mitochondria bioenergetics in normal and diabetic myocardium. Preliminary data have shown that hyperglycemia did not alter myocardial mitochondria function. Rather, insulin deficiency/insulin resistance plays a key role in the regulation of mitochondria function in diabetic myocardium. The proposed experiments will delineated a novel paradigm focused on insulin receptor signaling through Akt translocation to regulate mitochondria bioenergetics in normal and diabetic myocardium. The proposed experiments will identify the mitochondria substrates for insulin receptor signaling and determine whether modulating mitochondria-targeted Akt activation can reverse mitochondrial dysfunction in diabetic myocardium. Since mitochondria plays a key role in cardioprotection, understanding the mechanisms of insulin signal transduction to mitochondria will help design new strategies to prevent exacerbation of myocardial injury in insulin-deficient and insulin- resistant patients.